This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 4 |
| 6 | 9 |
| 7 | 23 |
| 8 | 62 |
| 9 | 167 |
| 10 | 461 |
| 11 | 1309 |
| 12 | 3784 |
| 13 | 11018 |
| 14 | 32431 |
| 15 | 96294 |
| 16 | 288246 |
| 17 | 868107 |
| 18 | 2629499 |
| 19 | 8005166 |
| 20 | 24482202 |
| 21 | 75177313 |
| 22 | 231697259 |
| 23 | 716488213 |
| 24 | 2222381516 |
| 25 | 6912569477 |
| 26 | 21556270329 |
| 27 | 67380727837 |
| 28 | 211080434346 |